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Cervical Lordosis Ratio as a Novel Predictor for the Loss of Cervical Lordosis After Laminoplasty
Kosei Ono,Sohei Murata,Mutsumi Matsushita,Hiroshi Murakami 대한척추신경외과학회 2021 Neurospine Vol.18 No.2
Objective: Maintaining cervical lordosis (CL) after laminoplasty is important for indirect decompression of the spinal cord. This study aimed to identify preoperative dynamic radiographic predictors for the loss of CL after laminoplasty. Methods: We retrospectively analyzed 141 consecutive patients who underwent cervical laminoplasty for cervical myelopathy. The following radiographic parameters were measured before surgery and at 1 year of follow-up: CL, C7 slope, C2–7 sagittal vertical axis (SVA), C2–7 range of motion (ROM), CL in flexion, CL in extension, ROM of flexion (Flex ROM), and ROM of extension. The CL ratio (CLR) was defined as 100×Flex ROM/C2–7 ROM. ΔCL was defined as postoperative CL minus preoperative CL. Patients were classified into 2 groups: group K (kyphotic change group, ΔCL ≤-10) and group C (control group, ΔCL >-10). Results: The patient population comprised 94 men and 47 women (mean age, 70.9±9.4 years), with 24 patients (17.0%) classified into group K. CL, C7 slope, and CLR were significantly higher in group K than in group C. The groups did not significantly differ in age, sex, C2–7 SVA, and C2–7 ROM. On multivariable analysis, the CLR was significantly associated with postoperative kyphotic changes. On receiver-operating characteristic curve analysis (area under the curve=0.717, p<0.001), the cutoff value for CLR was 68.9%, with sensitivity and specificity of 87.5% and 57.3%, respectively. Conclusion: The CLR, reflecting the balance between flexion and extension mobility, was identified as a novel predictor for CL loss after laminoplasty, with a cutoff value of 68.9%.
Kosei Tamura,Tohru Kamiya,Masafumi Oda,Yasuhiro Morimoto 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11
Root resorption is a pathological condition which is characterized by the loss of the tooth root. Root resorption is not painful in its early stages. As a result, many people who are potentially affected and the condition are often left untreated until it is detected during regular check-ups. If detected early, good treatment results can be achieved, whereas failure to treat the condition properly can lead to tooth extraction. However, the root resorption is currently difficult to detect on panoramic radiographs and may be treated as caries after it becomes painful. The aim of this paper is to identify root resorption from panoramic X-ray images using a deep metric learning algorithm. As a loss function for distance learning, it is known that the loss function in angle space is consistent. Therefore, a loss function is defined and trained using the cosine value of the angle between the feature and the center position to improve the discrimination performance. We obtained experimental results based on 150 image sets with 0.80 of accuracy, 0.62 of TPR, 0.19 of FPR and 0.78 of AUC, respectively.
Kosei Ono,Takayoshi Shimizu,Shunsuke Fujibayashi,Bungo Otsuki,Koichi Murata,Akio Sakamoto,Shuichi Matsuda 대한척추신경외과학회 2021 Neurospine Vol.18 No.1
Objective: Spinal meningioma is mostly benign, but they can exhibit neurological deficit. The relationship between neurological impairment and its radiographic findings, including intratumor magnetic resonance imaging (MRI) gadolinium enhancement and calcification in computed tomography (CT) scan, has not been studied. The purpose of this study was to investigate the association of preoperative image findings with neurological status in spinal meningioma. Methods: Patients histologically diagnosed with spinal meningioma (n=24), with an average age of 65.4 years, were included. The patients were classified into 2 groups, the homogeneous and heterogeneous groups, based on the contrast-enhanced T1-weighted MRI findings. Further, baseline demographics (age, sex, presence of preoperative paralysis [manual muscle testing 3 or worse neurological deficit in upper and/or lower limbs], tumor level, tumor length, and tumor occupation ratio), histological findings (Ki-67 index and histological subtypes), and CT findings (presence of intratumor calcification and Hounsfield unit [HU] value) were examined. Results: Preoperative paralysis was observed in 33.3% (8 of 24) of the patients. These patients exhibited frequent heterogeneous contrast-enhanced MRI findings than those without preoperative paralysis (57.1% vs. 14.3%, p=0.040). Further, preoperative paralysis did not associate with tumor level, tumor length, tumor-occupied ratio, Ki-67 index, and histological subtypes. The heterogeneous group showed 100% intratumor calcification and higher maximum HU than the homogeneous group (1,109.8 vs. 379.2, p=0.001). Conclusion: The heterogeneous contrast-induced MRI findings in the spinal meningioma were significantly associated with preoperative neurological impairment. Moreover, the intratumor contrast-deficient region in the heterogeneously enhanced tumors reflected marked calcification. The tumor hardness due to calcification may be related to preoperative neurological deficit.
Investigation of Bioactivity Mechanism of Flavonoids in Cancer Cells
( Kosei Yamauchi ),( Ayaka Tsuchiya ),( Tohru Mitsunaga ) 한국목재공학회 2021 한국목재공학회 학술발표논문집 Vol.2021 No.1
Quercetin is a flavonoid present as a glycoside in various fruits, vegetables as well as wood. Numerous studies have demonstrated that quercetin exhibits a variety of pharmacological effects including antioxidant, anti-inflammatory, and anti-cancer properties. The melanogenesis stimulatory activity and metastasis inhibitory activity of the quercetin derivatives were elucidated. Nineteen quercetin derivatives have been synthesized in order to investigate structure-activity relationships on the effect of melanogenesis and metastasis in B16 melanoma cells. 3,4’,7-O-trimethylquercetin (TMQ) significantly stimulated the extracellular melanin production. The compound stimulated melanosome transportation as well as the melanin synthesis in the cells. TMQ inhibited the migration in B16 melanoma cells. Additionally, it also inhibited migration and invasion in human ovarian cancer cell lines due to regulating the expression of MMP-2 and uPA that is relating to the metastasis. The target proteins of the methylquercetin were isolated and identified using pull down method in order to elucidate the direct mechanism. The investigation of binding site and energy between quercetin derivatives and the protein were under going.
Detection of the root resorption from panoramic X-ray images using deep metric learning
Kosei Tamura,Tohru Kamiya,Masashi Oda,Tatsurou Tanaka,Yasuhiro Morimoto 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10
Root resorption is a pathological process characterized by the loss of tooth roots because of inflammation induced by bacterial infection, trauma, physical or chemical irritation. As a result, the development of periodontal disease, increased susceptibility to infection and crooked teeth. In the worst case, it can lead to tooth extraction. Root resorption is often caused by pressure during orthodontic treatment. The presence of root resorption should be checked regularly during orthodontic treatment, as it often occurs. It is necessary to check for root resorption periodically during orthodontic treatment. However, it is difficult to detect the root resorption using a panoramic radiograph. As a result, root resorption is often latent and goes undetected. In this paper, we propose an image analysis method based on deep learning technique for detecting the root resorption on panoramic radiograph. We incorporate the EfficientNet for feature extraction in deep learning to the center loss and triplet loss as the loss function for metric learning. Our proposed method performed to 337 images which is obtained by panoramic radiograph. Accuracy of 71%, true positive rate of 77%, false positive rate of 30% were obtained.